1. Field of the Invention
The present invention relates to a method and device for processing into a convex spherical mirror form the end face of an optical fiber connector, a cylindrical material, or a block-shaped end face made of glass, ceramic, or plastic, and particularly to a method and device that can carry out processing with improved efficiency and accuracy.
2. Description of the Related Art
FIG. 1 is a schematic view showing the connection portion of the two end faces 8 of ferrule 21 of an optical connector 22 that has undergone a mirror grinding process to produce a convex spherical form. When two optical fibers 23 are connected and optical signals are propagated, every effort must be made to suppress the optical loss and reflection that occur at the gap between the end faces of the optical fibers. Currently, PC (Physical Contact) optical connectors 22 are widely employed as a method of realizing connections with low optical loss. In these PC optical connectors 22, end faces 8 of ferrules 21 provided at the ends of optical fibers 23 are formed with convex spherical mirror surfaces and the end faces of optical fibers 23 are brought into close contact.
When fabricating PC optical connector 22, surplus adhesive or surplus length of optical fiber may remain at the tip from the process of inserting and securing optical fiber 23 in ferrule 21. When mirror grinding end face 8 to a convex spherical form in a processing device of the prior art, this surplus adhesive or surplus optical fiber is first removed by coarse grinding, and then, as shown in FIG. 2, abrasive tape 2 is disposed over stage 3 having a surface for which the section is a concave arc, the end face of workpiece 1 is placed in contact with abrasive tape 2 and pressure applied, abrasive tape 2 is put in motion while confined to the upper surface of stage 3 in concave form, workpiece 1 is given a rotating and back-and-forth motion to transfer the concave surface shape of stage 3 to workpiece 1 by the grinding action of the abrasive tape and finish a smooth, convex spherical form (Refer to, for example, Japanese Patent Laid-open No. 029599/97).
The above-described ferrule end-surface spherical processing method of the prior art has the disadvantage of low processing efficiency because grinding fluid is not employed, and in cases in which grinding fluid is supplied as in normal grinding methods, there is the disadvantage that the amount of grinding fluid supplied becomes excessive, or that an appropriate amount of grinding fluid cannot be supplied in the processing of the spherical surface of the end face of the ferrule.